Water heating system



Dec. 16, 1941. H. MQBIEBEL WATER HEATING SYSTEM Filed March 31, 1941 Arrow/f Y Patented Dec. 16, 1941 2,266,152 WATER HEATING SYSTEM Herman M. Biebel,Elgin,alll.,asslnor"to lHcGraw Y Electric Company, lll., a corporation DelawareI Application March 31, 1941, serial N0.`3s5,9s0'

8 Claims.

My inventionl relates to control systems and particularly to hot water heating systems.

An object of my invention is to provide a hot water heating system which will continue heating of the Water even under periods of heavy load on circuits other than the water heater circuit in case of overload conditions on said other circuit.

Another object of my invention is to provide a water heating system having means for reducing the amount of energy translated into heat in the heaters associatedwith the water tank during periods of heavy loads on other circuits in a house.

Other objects of my invention will either be.

apparent from a description of one form of system embodying my invention or will be set forth in the course of such description and particularly in the appended claims.

In the single sheet of drawings,

Figure 1 is a generalized view of a hot water tank o f the ordinary domestic kind having associated therewith a system embodying my invention, and

. Fig, 2 is a modified form of system embodying any kind of electric heater either mounted on the outside of the tank or extending through the tank wall into direct engagement with the water. The lower tank heater I3 is preferably mounted at a lowermost point of the tank and it is to be understood that the upper heater I5 may be mounted at any desired point along the upper part oi the tank, the amount of water aiected directly by said upper heater being, of course, in proportion to its position on the tank.

I provide an electromagnetically controlled switching means I1 -including a rst ilxed contact member I9, a second xed contact member 2| spaced apart from the rst xed contact member, and a movable contact arm 23 so designed and constructed as to be normally yieldingly biased into engagement with fixed contact member I9.

A conductor 25 connects ilxed contact member l I9 with a fixed contact member 2l of a thermal switch 23 which includes in addition to the fixed (Cl. E19-39) lil contact member 21, a bimetal bar 3| having -its iixed end so mounted relatively to the tank II as to be in direct heat-receiving relation therewith. It is to be noted that the bimetal bar 3| will normally engage xed contact member 2l as long as the thermal switch 29 is subject to cold water but that bimetal bar 3| will ex out of engagement with contact 2l when all or substantially all of the Water in the tank has been heated to a predetermined high temperature, all in a manner Well known in the art. One terminal of heater I3 is electrically connected with the xed mounting of bimetal bar 3| while the other end of heater I3 is connected by a conductor 33, through a suitable fuse 35, with one bus bar 31 of a panel board 33. The panel has mounted thereon a second bus bar 4| and the two bus bars are connected through suitable fuses with supply circuit conductors 43 and 45. It is to beunderstood that the showing of the panel board is general only since it is such as is now used in electric installations and forms no part of my invention. Contact member 21 is connected by a conductor 4l to one terminal of the upper heater I5, the other terminal of which is connected by a conductor 43 to a xed contact member 2| of switch Il. Movable Contact arm 23 of switch Il is connected by a conductor 5| with bus bar 4| and therefore with the other supply circuit conductor ,45,

I have shown an electromagnet including a coil 53 and a. xed magnetizable core 55 to cause movement of contact arm 23 out of engagement with fixed contact I9 and into engagement with fixed contact 2| under conditions to be hereinafter described. A second electric load circuit is shown generally as by numeral 5l and includes a conductor 59 connected through suitable fuses with bus bar 4| and a conductor 6|, one end of which is connected to one terminal of coil 53, the other terminal of which is connected-by a conductor 63 with bus bar 3l.

I have illustrated a plurality of lamps B5 each controlled by a suitable switch, an electric motor 51 and a. plurality of electric resistors 69 as being connected between conductors 59 and 6|. I desire to illustrate thereby that I may connect the electromagnet and particularly its coil 53 in circuit with someother part of the usual house load, such as incandescent lamps 65 or the electric range represented by the resistors 53, to

controll the energization of the tank heaters, in'

accordance with the load conditions in said second circuit.

As long as less than all of the water in the tank to and through the engaged members 21 and 3|,

through heater I3 and from there through conductor 33 and bus bar 31 to the other supply circuit conductor 43.

, I wish to. here point out that the` amount ofI electrical energy translatable into heat in the lower heater I3 and the upper heater I5 may be alike or different and if it is desired, when permitted by my control system,l to energize heater i5 to quickly obtain hot water in the upper part of the tank, `the upper heater I5 may be designed to translate a larger amount of electric energyinto heat than the lower heater although it may be preferable to make the two heaters I3. and I5 of like energy consumption.

As soony as substantially all of the water in the tank has been heated to a predetermined temperature, the thermal switch 29 will cause deenergization` of heater I3 even though contact arm 23 may still be in engagement with the fixed contact I9.

Let it be assumed, however, that while bimetal bar 3| is still in engagement with fixed contact -member 21, the current in the other circuit exceeds a predetermined limit or value making it desirable to continue energization of the heatersand heating of the water in the tank I only under certain operatingvconditions, this being effected as follows: 'I'he overload current in coil 53 causes movement of contact arm 23v into engagement with fixed contact 2| whereby a different heater energizing circuit is effected substantially as, from Asupply circuit conductor 43 to bus bar 31 and through conductor 33 to heater I3, to and through the thermal switch 29'which is in closed position, through conductor 41 an'd heater I5 through conductor 49 to contact 2|, to engaged contact arm23 Vand from there through conductor 5| to bus bar 4I and tothe other supply circuit conductor 45.

ing a exing bimetal bar 15 having one end mounted on a suitable contact member and in heat-receiving engagement with the tank II and including also a xed contact member 11. One terminal of heater i3 is connected to the iixed end of bimetal bar 3| and xed contact member 21 is connected by a conductor d1 with one terminal of heater i5, the other terminal of which is connected to the fixed support of bimetal bar 15. Contact member l1 of the upper thermal switch 13 is connected by a conductor 19 with fixed contact member 2|. All of the other parts shown in Fig. 2 are the same as were shown in Fig. 1 and are therefore provided with the same numerals.

The plural-contact plural-position switch I1 is shown in Fig. 2 of the drawing as in a position where contact arm 23 is in engagement with xed contact member I9 this being the case when the load in the second electric load circuit `is less than a predetermined value, which will cause energization of heater I3 alone to cause heating of the water in case less than, substantially all of the water in the'tank is hot.

y of the lower thermal switch 29 is shown as being in engagement with fixed contact member 21 indicating the presence of enough cold water in the tank to affect the lower thermal switch 29.

Let it now be assumed that say the resistors v69 in the second circuit hereinbefore described are energized, causing heavy current to ilow through coil 53 with the result that contact arm 23 is f moved so as to electrically engage fixed contact member 2 I If the tank contains such a relatively small quantity of hot water that bimetal bar 15 of the upper thermal switch 13, is in electrical.

through the closed switch 13 to and through upper heater I5, through conductor 41 to and through the lower closed thermal switch 29 to and through the lower heater I3 and from there through conductor 33 to 'bus bar 31 and from/there to the other supply circuit conductor 43.

It is therefore evident that should it be considvered necessary to continue heating water in the tank I'I even during the periods of overload on another house circuit, this will be effected since I the upper heater is now connected in the circuit and lin series circuit relation relatively to the lower heater I3 whereby, of course, reducing the It is evident, therefore, that under these conditions both heaters I3 and I5 will be energized in case' the tank contains less than a predetermined fractional amount of hot water which amount must be -suiiicient to cause flexing of the bimetal bar 15 out of engagement with contact 11 to preamount Cof energy .translated into heat for heating I the water in the tank during the periods of excess or overload in another house circuit. The ener-1 gization'of the upper heater, I 5 will cause water in the upper part of the tank to be heated, if merels little or nohot water in the tank, thereby ensuring the presence of at least a small quantity of hot water for use.

Referring now to Fig. 2 of the drawing, I have there illustrated 'a modification of the systemshown in Fig. 1 ofthe drawing and all parts in Fig. 2 similar to lthose in Fig. 1 are provided with the same numerals. I provide a lower heater I3 and an upper heater vI5 together with a 'lower thermally actuable switch 29 but in addition I provide an upper thermally actuable switch 13 similar to the lower thermal switch 29 and includvent the hereinbefore described energization of both heaters during the times of relatively heavy loads on some house circuit other than that including the tank heaters.

It is further to be pointed out that the amount of energy in heater I3 now translated into heat is less than was the case .when heater I3 alone was energized as during the period of light'loads in the second circuit and further, that the total' amount of electrical energy translated into heat in both heaters is less than was the case during the periods of normal load' in the second Various modifications may be made in the sysand described and all such modifications clearly coming within the scope of the appended claims are to be considered as being covered thereby. I claim as my invention: y 1. A control system for a lhot water tank comprising an electric circuit having an upper and a lower electric heater for the tank connected The bimetal member 3| therein, switching means for said heaters normally biased into position to effect energization oi' said lower heater in case less than all of the water in the tank is hot, a second electric load circuit and an electromagnet carrying the current of said second circuit and effective, when the current therein exceeds a certain value, to move said switching means into a second position to effect energization ,of both said heaters in series electric circuit with each other in case the tank contains a predeterminedquantity of cold water at the time when the current in said second circuit exceeds said certain value.

2. A control system i'or a hot water tank comprising an electric circuit having an upper and a lower electric heater for the tank connected therein, switching means for said heaters, a second electric circuit and electromagnetic means controlled by the current in said second circuit and eilective, when the current value in said second circuit is below a predetermined limit, to cause energization of said lower heater only as long as less than all of the water in the tank is hot and to cause energization of both said heaters in series electric circuit with each other as long as the tank contains a predetermined amount of cold water, during such time as the current value in said second circuit is above said predetermined limit.

3. A control system for a hot water tank comprising an electric circuit having an upper and a prising an electric circuit having an upper and l a lower electric heater for said tank connected therein, a thermal heater control switch effective to cause deenergization oi said heaters when substantially all of the water in the tank is hot, switching means for said heaters, a second circuit, electromagnetic means controlled by the current in said second circuit and electric connections between said heaters, said thermal switch and said switching means for causing energization of the lower heater only during periods of normal load in said second circuit in case less than all oi' the water in the tank is hot, for causing energization of both said heaters in series electric circuit with each other during periods when the load in said second circuit is above normal value and less than all of the water in the tank is hot and for causing deenergization' of both said heaters when substantially all of the water in the ytank is hot.

4. A control system for a hot water tank comprising an electric circuit having an upperand a lower electric heater for said tank connected therein, a thermal heater control switch ei'iec-v tive to cause deenergization of saidheaters when substantially all oi the-,water in the tank is hot, switching means for said heaters, a second circuit, electromagnetic meanscontrolled by the current in said second circuit and electric connections between said heaters, said thermal switch and said switching means for selectively causing energization of the lower heater alone and of both heaters at the same time in accordance with the value oi the current in said second circuit.

5. A control system for a hot water tank comprising an electric circuit having an upper and a lower electric heater for said tank connected therein, a thermal heater control switch eective to cause deenergization o! said heaters when subvperiods of time when theload in the stantially all of the water in the tank is hot, switching means for said heaters, a second circuit, electromagnetic means controlled by the current in said second circuit and electric connections between said heaters, said thermal switch and said switching means to cause the number of heaters energized to increase and the energization of the lower heater to decrease with a predetermined increase in the current in said second circuit.

6. A control system for a hot water tank comprising an electric circuit having an upper and a lower electric heater for said tank connected therein, a thermal heater control 'switch eiective to cause deenergization of said heaters when substantially all oi the water in the tank is hot,

lower electric heater for said tank connected therein, an upper and a lower thermal heater control switch, switching'means for said-heaters, a second circuit, electromagnetic means controlled by the current in said second circuit and electric connections between said heaters. said thermal switches, said switching means and said circuits to selectively cause energization of the lower heater only during periods of normal load in said second circuit in case less than all of the water in the tank is hot and to cause deenergization of the lower heater when substantially all of the water in thetank is hot, to cause energization of both heaters in series electric circuit with each other during periods when the lload-in said second circuit is above normal value and in case the tank contains less than a predetermined amount of hot water and to cause deenergization of both heaters `when the tank contains more than said predetermined amount of hot water.

8. A control system for a hot water tank comprising a first electric circuit having an upper and a lower electric heater for the tank connected therein, a second electric circuit having a variable load connected therein and means consisting ot an upper and a lower thermal heater control switch, an electromagnetic switch for the first circuit controlled by the current in the second circuit and electric connections between the upper and the lower thermal switches, the upper and the lower heaters, the electromagnetic switch and the two circuits to ensure that substantiallyallotthewaterinthetankshallbe hotduringthoseperiodsottimewhentheload inthesecondcircuiti'sbelowacertainvalue and to ensure that a predetermined quantity o! waterinthetankshallbehotduringthose A secondcircuitisabovesaideertainvalue.

HIRMANILBIEBEL. 

